And if you like, you can marry your private cloud with Amazon's public cloud by way of a so-called cloud management service from RightScale, also bundled with the Jackalope.

In this case, a cloud is collection of pooled computing resources - that's not called a grid. "Clouds are on-demand," Rich Wolski, the University of California, Santa Barbara who heads the Eucalyptus project, tells The Reg. "Grids tend to work with systems where a small number of resources can acquire all of the resources. Users have to wait - in line, typically - in order to gain access to the resources. It's called batch scheduling. Clouds are not batch scheduled. Clouds are immediate."

Plus, he says, clouds are "self service." And grids aren't. "When you sit down at a cloud - you as the end user - you can choose how that cloud should be configured for your needs. When you sit down at a grid, you have to run your application according to the way the administrator has configured it."

And we trust Rich Wolski. He has a knack for exploiting Martha Stewart.

In any event, Jackalope's "Universe" archive includes the free Eucalyptus, short for "Elastic Utility Computing Architecture for Linking Your Programs To Useful Systems." Canonical will offer front-line support for the platform, with Wolski and his Eucalyptus team providing tier three support when the questions really get interesting.

Meanwhile, the Jackalope's default Eucalpytus installation gives you the option of registering your cloud with RightScale, a California outfit that seeks to ease the difficulty of running applications across multiple clouds - both public and private.

RightScale initially sprung up to provide a slick web front-end for Amazon EC2. But now that Amazon offers its own web interface, RightScale has expanded its online service to juggle similar public clouds from GoGrid and FlexiScale.

The idea is that RightScale will let you grab resources from multiple clouds as you need them. "We believe that there are every interesting hybrid use cases, some workloads my be internal. Some may be external," says RightScale co-founder Thorsten von Eicken. "We want to make this as easy as we can."

But von Eicken admits that these are early days. "To be frank, we want to see what people actually do," he tells us. "There's so much hypothesizing, wishful thinking going on in the cloud space. I'm in favor of saying 'Here's something real. It may not be complete. But let's see if it makes sense.' After all, it always comes back to reality."

Amen to that.

The reality is that RightScale's Ubuntu integration goes live on Tuesday night. And the Jackalope hits the web with Eucalpytus two days later.

RightScale doesn't yet offer cloud migration from Ubuntu to GoGrid or Flexiscale. But presumably, this is on the way. Running Rightscale with your private cloud is free, and the company begins charging when you expand to EC2 or setup redundant servers in-house.

"You may want to try things out in house. You may be more comfortable than that," von Eicken says. "Then you may want to deploy in the public cloud to get scalability, connectivity etc."

Or, if you've already deployed an app on EC2, you may go the other way. "You may have outsourced development. That might be easier in the public cloud. But then you may want to bring things in-house for production because of regulatory requirements or the like." ®